1. Technical Field
The invention relates to inserter systems included in mailing machines, for assembling documents into batches or into collations and then for inserting the collations into envelopes. More particularly, the invention is directed to control systems for such inserter systems, and even more particularly to controlling the spacing between documents being handled as they are being fed from a stack of documents.
2. Description of Related Art
Inserter systems capable of generating up to 18,000 mail pieces per hour are well known in the art and are generally used by organizations that produce a large volume of mailings where the content of each mail piece varies. Often, the inputs to an inserter system are computer-generated and printed documents, with each document containing information intended for a particular addressee. The documents may originate from a stack of cut sheets or from a web of forms. It is the function of the inserter system to accept the documents and produce the individual mailings that correspond to each document. To accomplish this, the typical inserter includes a variety of modules for performing different tasks on the documents passing through the inserter. Typical modules are: various web handling modules (slitters, cutters and bursters) for separating the continuous forms into singular or discrete documents, a sheet feeder module for feeding individual cut sheets, an accumulator module for assembling the sheets and/or form documents into a collation, a folder module for folding the collation into a desired configuration (Z-fold, C-fold, half fold), a conveyor/staging module for transporting and queuing the collation, a plurality of enclosure feeder modules for assembling and adding a packet of enclosures to the collation, an insert station module for inserting the collation into an envelope, and a control system to synchronize the operation of the overall inserter system to assure that the collations are properly assembled. Examples of such inserter systems are the 8 Series(trademark) and 9 Series(trademark) inserter systems available from Pitney Bowes, Inc., Stamford, Connecticut.
Typically, information for control of such inserter systems is read from a control document by a scanner associated with the most upstream module in the inserter system. The control document is generally an address bearing document and contains information specific to a particular addressee.
Additionally, each control document contains control information for instructing the downstream modules on how to assemble a particular mail piece. Once scanned, the control information is transmitted to the control system of the inserter system; the control system monitors the processing of the collation through each module. Generally, the control document includes a barcode type control code or other machine-readable markings defining the number of forms or sheets to be accumulated into the collation, the number of enclosures from each of the enclosure feeder modules to be assembled to the collation, and information for other purposes, such as the selection of appropriate postage.
The enclosures assembled to a collation at an enclosure feeder modules are of two types, either generic or specific. The generic enclosures (advertisements, notices, business return envelopes, etc.) are of a general type that are not specifically directed to any particular addressee. Therefore, generic enclosures serve each addressee equally well. On the other hand, specific enclosures (canceled checks, invoice statements, etc.) contain unique information that is directed to a particular addressee. Providing mail pieces with specific enclosures is commonly referred to in the industry as matched mailing; specific enclosures are only meaningful for the appropriate addressee and thus must be matched to each addressee.
An example of a mail piece containing specific enclosures that can be produced by an inserter system is a monthly checking account statement which includes a summary of all account activity (documentsxe2x80x94input from the web or sheet feeder modules) and the canceled checks (specific enclosuresxe2x80x94input from the enclosure feeder modules). Accordingly, the account summary and the canceled checks associated with the account must be matched together by the inserter system prior to insertion into the envelope.
Therefore, in matched mail applications, a high degree of synchronization must be incorporated into the inserter system for it to function properly. Continuing with the example from above, the canceled checks must be placed into the enclosure feeders in a known order. In similar fashion, the account summaries must be input into the insert system in a corresponding order. In a typical operation, the control document will contain the name, address and account number of a particular addressee. The control code on the control document will inform the inserter system of the number of subsequent following sheets/forms that are necessary to complete the account summary. In response, the inserter system will collect the control document and subsequent sheets/forms in the accumulator module to form a collation. Once completed, the collation advances to the folder module for folding into a desired configuration. After folding, the collation advances to the conveyor/staging module. At this point, the insert system instructs the enclosure feeder modules to feed and collect a packet of enclosures based on information contained in the control code. For example, the insert system may instruct a first enclosure feeder module to feed five enclosures, and a second enclosure feeder module to feed ten enclosures. Next, the document collation is combined with the packet of enclosures to form a new collation, which is then fed downstream for further processing such as inserting it into an envelope. Therefore, it is understood that without a high degree of synchronization, or if something occurs to disturb the synchronization, problems in producing proper matched mailings can occur.
The prior art uses so-called motion control profiles to express, as a function of time, the velocity/speed of an axis of a motor that causes motion of a sheet in a mailing system. A motion control profile consists of a series of segments, each segment having a duration and each corresponding to a state of motion of an axis of a motor ultimately responsible for imparting motion to a sheet or envelope.
In the particular case of a matched mailing in which an inserter provides a customer bank statement along with corresponding canceled checks, a check feeder (enclosure feeder) feeds checks for a collation (of a mail piece) until an account divider page is encountered indicating to the check feeder the end of the checks for the collation. According to the prior art, a check feeder typically operates according to what is referred to as a continuous stream (motion control) profile. Feeding enclosures according to a continuous stream profile has a relatively high risk of jamming and other integrity-compromising events, a risk that is more significant when feeding checks (which are fed width-wise) than when feeding other kinds of enclosures because of the shorter width of checks compared to the widths of other kinds of enclosures.
It would be advantageous to modify the prior art motion control profile for a check feeder (or other, similarly operating insertion module) so as to lessen the risk of jams or other integrity-compromising events.
Accordingly, a first aspect of the invention provides a control system for controlling the operation of a motor driving a separator roller of a collation-feeder stager assembly of an enclosure feeder module of an inserter system, the inserter system including an input section for producing a sequence of collations, transport means for feeding the sequence of collations in a path of travel, and a chassis section, downstream from the input section, having one or more enclosure feeders, the collation-feeder stager assembly including a following roller assembly having a first and a second, following, set of rollers, the control system comprising: an edge sensor, disposed so as to have a line of sight suitable for sensing the arrival between the first and second set of the following roller assembly of a leading or trailing edge of a collation, and for providing signals indicating the arrival of the leading or trailing edge of the collation; and a controller, responsive to the signals indicating the arrival of the leading or trailing edge of the insertion, for determining a motion control profile for the motor designed to maintain within a predetermined range a gap between collations; wherein the controller decelerates the separator roller upon receiving a signal from the edge sensor indicating the arrival of a leading edge.
In accord with the first aspect of the invention, the motion control profile may include a first higher constant speed segment, followed by a minimum constant speed segment followed by a second higher constant speed segment, wherein the speed of the first higher constant speed segment may be predetermined as may be the speed of the second higher constant speed segment, and further wherein the controller may adjust the speed used for the minimum speed segment and the deceleration of the motor between the first higher speed segment and the minimum speed segment and also the acceleration between the minimum speed segment and the second higher speed segment, thereby lengthening or shortening the three segments and so affecting the gap between successive collations being fed by the enclosure feeder, the lengthening or shortening being calculated by the controller to cause a gap within a predetermined range. Further, the speed of the minimum speed segment may also be pre-determined. In other applications, the separator roller may accelerate the separator roller from the minimum speed segment to the second, higher constant speed segment either upon receiving a signal from the edge sensor indicating the arrival of a trailing edge, or after a predetermined maximum time at minimum speed elapses, whichever occurs earlier.
Also according to a first aspect of the invention, the motor may be a stepper motor.